CVE-2022-48884 net/mlx5: Fix command stats access after free
A use-after-free vulnerability in the Linux kernel mlx5 driver allows local attackers to cause a system crash via NULL pointer dereference.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2022-48884?
CVE-2022-48884 is a medium-severity use after free vulnerability in Linux kernel, published on 21 Aug 2024. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
net/mlx5: Fix command stats access after free
Command may fail while driver is reloading and can't accept FW commands till command interface is reinitialized. Such command failure is being logged to command stats. This results in NULL pointer access as command stats structure is being freed and reallocated during mlx5 devlink reload (see kernel log below).
Fix it by making command stats statically allocated on driver probe.
Kernel log: [ 2394.808802] BUG: unable to handle kernel paging request at 000000000002a9c0 [ 2394.810610] PGD 0 P4D 0 [ 2394.811811] Oops: 0002 [#1] SMP NOPTI ... [ 2394.815482] RIP: 0010:native_queued_spin_lock_slowpath+0x183/0x1d0 ... [ 2394.829505] Call Trace: [ 2394.830667] _raw_spin_lock_irq+0x23/0x26 [ 2394.831858] cmd_status_err+0x55/0x110 [mlx5_core] [ 2394.833020] mlx5_access_reg+0xe7/0x150 [mlx5_core] [ 2394.834175] mlx5_query_port_ptys+0x78/0xa0 [mlx5_core] [ 2394.835337] mlx5e_ethtool_get_link_ksettings+0x74/0x590 [mlx5_core] [ 2394.836454] ? kmem_cache_alloc_trace+0x140/0x1c0 [ 2394.837562] __rh_call_get_link_ksettings+0x33/0x100 [ 2394.838663] ? __rtnl_unlock+0x25/0x50 [ 2394.839755] __ethtool_get_link_ksettings+0x72/0x150 [ 2394.840862] duplex_show+0x6e/0xc0 [ 2394.841963] dev_attr_show+0x1c/0x40 [ 2394.843048] sysfs_kf_seq_show+0x9b/0x100 [ 2394.844123] seq_read+0x153/0x410 [ 2394.845187] vfs_read+0x91/0x140 [ 2394.846226] ksys_read+0x4f/0xb0 [ 2394.847234] do_syscall_64+0x5b/0x1a0 [ 2394.848228] entry_SYSCALL_64_after_hwframe+0x65/0xca
Weakness: CWE-476
Which versions are affected by CVE-2022-48884?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2022-48884?
Apply the vendor's patch.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2022-48884 being exploited?
There is no known exploitation of CVE-2022-48884 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as DEBIAN-CVE-2022-48884, GHSA-6vhv-fv5r-vfg6, UBUNTU-CVE-2022-48884.